All Hollywood wants for Christmas is a better way to predict the box office.

With the traditional system for forecasting hits, known as “tracking,” under fire, the film industry is increasingly turning to social media and other online signposts to help figure out what will resonate with audiences.

Getting a grip on pre-buzz is key for movie marketing and release strategies. The decades-old system — consisting of focus groups, exit polls, pre-release tracking interviews — is starting to show its age.

Traditional tracking services have made several bad calls this year. For instance, “The Conjuring” and “The Butler” did much better than expected, while “Kick Ass 2” failed to pop as predicted.

One studio boss said that tracking services tend to give a true picture just days ahead of a release — too late to redirect ad dollars. Social media, meanwhile, can help provide guidance much earlier.

Enter a slew of new players aiming to fill in the gaps.

Aside from tweets and “likes,” indicators such as how many times a trailers have been played can predict the success of a movie, while spikes in Twitter hashtags can indicate a rival just kicked off a big marketing campaign.

“There are other digital channel indicators that also help tell critical stories about the prospects for a film’s success — search volume, trailer views and clips on YouTube,” said Jason Klein, co-founder of ListenFirst Media. “This fuller picture helps give a better sense of success or failure in the marketplace.”

ListenFirst and other newcomers are starting to build big data troves of movie statistics from sources such as Instagram and Tumblr as well as Twitter and Facebook.

The company’s data show that “Hunger Games: Catching Fire” has the biggest social fan base of holiday movies, with 12.45 million Facebook fans and Twitter followers. “Thor: The Dark World,” ranks second, with 8.5 million, followed by “The Hobbit: The Desolation of Smaug,” with 3.5 million.

Twitter and Facebook are also making the Hollywood rounds to talk up their effectiveness in getting people to the theaters.

And Google just released a big film study earlier in the summer touting trailer searches as one of the key leading indicators of interest in movies.

Movie title searches on Google rose by 56 percent last year, according to a document obtained by The Post. Google also pitched the idea that YouTube title searches had a strong correlation with a film’s opening performance.

Social media is bolstering its box-office tracking abilities while also expanding its potential as a marketing platform. Weinstein Co., for instance, recently ran an element of its “The Butler” campaign on business social-networking site LinkedIn.

One studio exec said digital outlets are key for targeting viewers who don’t spend time with TV or print.

“You have to put money into digital because if you don’t you’re going to miss people who are getting information from their phones and tablets and computers.”